UL fire rating:
A: Horizontal fire test
B: VW-1: Vertical fire test, drips cannot ignite the cotton wool.
VW-1SC: Vertical fire test, insulated core wire and finished wire are tested separately.
C: CL2 (VERTICAL TRAY FLAM TEST):
Perform a vertical combustion test in a closed combustion box (similar to UL1581 in a closed building)
D: CL2R (RISET CABLE)
E: CL2P (PLENUM CABLE)
F: CM (COMMUNICATION CABLE communication line); G: CMR; H: CMP.
The content of UL plastic material 94-V0 (94V0 is the so-called flame-retardant grade, divided into 5 grades) 94-V0 When the fire is burned, it will be extinguished immediately and will not ignite spontaneously.
94-V1 When the fire is burning, the fire will burn for 1 second and then extinguished immediately without spontaneous combustion
94-V2 When the fire is burning, it will burn for 2 seconds and then extinguished immediately without spontaneous combustion
94-V5 When the fire is burning, the fire will burn for 5 seconds and then extinguished immediately without spontaneous combustion
94-HB When the fire is burning, it will burn until only carbon is left
Comparison of UL94 Plastic Flame Retardant Grade and UL 1581 VW-1 Flame Retardant Grade
There are 12 types in UL94: HB, V-0, V-1, V-2, 5VA, 5VB, VTM-0, VTM-1, VTM-2, HBF, HF-1, HF-2.
The flammability UL94 rating is the most widely used plastic material flammability performance standard. It is used to evaluate the ability of a material to extinguish after being ignited. According to the burning speed, burning time, anti-drip ability and whether the drops are burning, there are many ways to judge. Many values can be obtained for each tested material according to color or thickness. When the material of a certain product is selected, its UL rating should meet the thickness requirements of the wall part of the plastic part. The UL rating should be reported together with the thickness value. It is not enough to report the UL rating without the thickness.
The flame retardant grades of plastics are gradually increased from HB, V-2, V-1, V-0, 5VB to 5VA:
HB: The lowest flame retardant grade in the UL94 standard. It is required that for samples with a thickness of 3 to 13 mm, the burning rate is less than 40 mm per minute; for samples with a thickness of less than 3 mm,
The burning rate is less than 70 mm per minute; or it goes out before the 100 mm mark.
V-2: After two 10-second combustion tests on the sample, the afterflame extinguished within 60 seconds. The dripping particles can ignite cotton.
V-1: After two 10-second burning tests on the sample, the afterflame extinguished within 60 seconds. The dripping particles cannot ignite the cotton.
V-0: After two 10-second burning tests on the sample, the afterflame extinguished within 30 seconds. The dripping particles cannot ignite the cotton.
5VB: After five seconds of burning test on the sample, the afterflame will be extinguished within 60 seconds. The dripping particles cannot ignite the cotton. For block samples, it is allowed to be burned through.
5VA: After five seconds of burning test on the sample, the afterflame will be extinguished within 30 seconds. The dripping particles cannot ignite the cotton. For block samples, it is not allowed to be burned through.
